Liquid Fuel Combustion Chemistry
Future propulsion systems require an understanding of turbulence-chemistry interaction under high-speed, highly-turbulent flow regimes. Under such conditions, fuel properties and combustion characteristics are key factors that can affect engine performance. Among available fuel options, liquid hydrocarbon-based fuels are the current choices with their high energy density values. However, complexity in fuel composition and molecular structures precludes detailed modeling of their combustion behavior.
I proposed a physics-based HyChem (hybrid chemistry) approach (my Ph.D. work) to address the above problem. Initial fuel pyrolysis is treated with a lumped reaction model with parameters determined from kinetic experiments. The subsequent, rate-limiting oxidation process is described by a detailed, foundational fuel chemistry model (FFCM). The HyChem approach was tested to model the combustion of many practical fuels with high prediction accuracy, including conventional jet fuel, rocket propellants, a sustainable aviation fuel, and gasolines. Through collaborations, the HyChem models were successfully implemented in CFD simulations of turbulent spray combustion in real combustors, thus resolving a long-standing issue of simulating real-fuel turbulence-chemistry interactions under real engine conditions. HyChem has also been extended to predict emissions (i.e., NOx and soot) and the effect of exhaust gas recirculation (EGR).
Related publications
- Y. Zhang, W. Dong, R. Xu, H. Wang*, Foundational Fuel Chemistry Model 2 – iso-Butene chemistry and application in modeling alcohol-to-jet fuel combustion, Combustion and Flame, 259, 113168, 2024. [Link] [PDF]
- A.M. Chang, J. Meisner, R. Xu, T.J. Martínez*, Efficient acceleration of reaction discovery in the ab initio nanoreactor: Phenyl radical oxidation chemistry, The Journal of Physical Chemistry A, 127, 9580-9589, 2023. [Link] [PDF]